On a not heavily modified default installation, the check pmp-check-mysql-file-
privs gives the following warning by default:

WARN files with wrong ownership: /var/lib/mysql/debian-10.11.flag

(
For systems that have been upgraded, it is probably even more:
WARN files with wrong ownership: /var/lib/mysql/mysql_upgrade_info
/var/lib/mysql/debian-10.5.flagWARN
)

Of course, a workaround would be to chown those files, since that should not do
much harm, but it might be nice to just patch the check to ignore those
(debian-specific) files.